Clutch assemblies selectively transfer rotational motion between a power source and a driven member. By selectively engaging multiple stages of clutch assemblies within a transmission, the ratio of input rotation to output rotation is varied. Known clutch assemblies utilize multiple friction plates interposed between multiple reaction plates. An actuator is energized when the clutch is engaged so that the faces of the reaction plates and friction plates engage to transfer torque between the friction plates and reaction plates. As higher reaction loads are required, the number of plates is typically increased to increase the reaction surface area.
When the clutch is disengaged, the friction plates and reaction plates are separated by a minimal distance to maintain a low travel required to engage the clutch and/or to minimize the size of the clutch assembly. The relative movement between the friction plates and reaction plates as the friction plates rotate causes the fluid between the plates to be worked, causing heating of the fluid. Such an assembly is susceptible parasitic losses due to the friction between the adjacent, but unengaged plates, thereby reducing the power transferred through the transmission by the resistance to rotation of the plates when the clutch is de-energized, causing the clutch to unnecessarily consume power.